var notInTags = [
	  'a', 'code', 'head', 'noscript', 'option', 'script', 'style',
	  'title', 'textarea'];
var textNodeXpath =
  	".//text()[not(ancestor::"+notInTags.join(') and not(ancestor::')+")]";
// Built based on:
//  - http://en.wikipedia.org/wiki/URI_scheme
//  - http://www.regular-expressions.info/regexbuddy/email.html
var urlRE = new RegExp(
    '('
    // leading scheme:// or "www."
    + '\\b([a-z][-a-z0-9+.]+://|www\\.)'
    // everything until non-URL character
    + '[^\\s\'"<>()]+'
    + '|'
    // email
    + '\\b[a-z0-9._%+-]+@[a-z0-9.-]+\\.[a-z]{2,4}\\b'
    + ')', 'gi');
var queue = [];

/******************************************************************************/

linkifyContainer(document.body);
document.body.addEventListener('DOMNodeInserted', function(event) {
	linkifyContainer(event.target);
}, false);

/******************************************************************************/

function linkifyContainer(container) {
	// Prevent infinite recursion, in case X(HT)ML documents with namespaces
	// break the XPath's attempt to do so.	(Don't evaluate spans we put our
	// classname into.)
	if (container.className && container.className.match(/\blinkifyplus\b/)) {
	  return;
	}

	var xpathResult = document.evaluate(
		  textNodeXpath, container, null,
		  XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);

	var i = 0;
	function continuation() {
		var node = null, counter = 0;
		while (node = xpathResult.snapshotItem(i++)) {
		  var parent = node.parentNode;
		  if (!parent) return;

		  // Skip styled <pre> -- often highlighted by script.
		  if ('PRE' == parent.tagName && parent.className) continue;
		  
			linkifyTextNode(node);

			if (++counter > 50) {
				return setTimeout(continuation, 0);
			}
		}
	}
	setTimeout(continuation, 0);
}

function linkifyTextNode(node) {
	var i, l, m;
	var txt = node.textContent;
	var span = null;
	var p = 0;
	while (m = urlRE.exec(txt)) {
		if (null == span) {
			// Create a span to hold the new text with links in it.
			span = document.createElement('span');
			span.className = 'linkifyplus';
		}

		//get the link without trailing dots
		l = m[0].replace(/\.*$/, '');
		var lLen = l.length;
		//put in text up to the link
		span.appendChild(document.createTextNode(txt.substring(p, m.index)));
		//create a link and put it in the span
		a = document.createElement('a');
		a.className = 'linkifyplus';
		a.appendChild(document.createTextNode(l));
		if (l.indexOf(":/") < 0) {
			if (l.indexOf("@") > 0) {
				l = "mailto:" + l;
			} else {
				l = "http://" + l;
		  }
		}
		a.setAttribute('href', l);
		span.appendChild(a);
		//track insertion point
		p = m.index+lLen;
	}
	if (span) {
		//take the text after the last link
		span.appendChild(document.createTextNode(txt.substring(p, txt.length)));
		//replace the original text with the new span
		try {
			node.parentNode.replaceChild(span, node);
		} catch (e) {
			console.error(e);
			console.log(node);
		}
	}
}